The invention relates to a decoder element for generating an output signal having three different potentials, and an operating method for the decoder element.
It is accordingly an object of the invention to provide a decoder element for generating an output signal having three different potentials and an operating method for the decoder element which overcomes the above-mentioned disadvantages of the prior art devices and methods of this general type, which generates, at an output, an output signal which can assume three different potentials as a function of input signals of the decoder element.
With the foregoing and other objects in view there is provided, in accordance with the invention, a decoder element containing an output outputting an output signal having one of three different potentials including a first potential, a second potential, and a third potential. The second potential lies between the first potential and the third potential. A first terminal and a potential terminal having a value of the second potential impressed thereon are provided. A first series circuit is provided and is formed of a first transistor of a first conductivity type and a second transistor of a second conductivity type connected in series with each other and connected to the first terminal. The second transistor has a control terminal connected to the potential terminal, and the first transistor has a control terminal. The first terminal is connected to the output through the first series circuit. A third transistor of the first conductivity type having a control terminal and connected between a second terminal and the output is provided. A fourth transistor of the second conductivity type connected between the output and the potential terminal is provided and has a control terminal. A third terminal is connected to the control terminal of the third transistor and to the control terminal of the fourth transistor. A fifth transistor of the first conductivity type having a control terminal is provided. The fifth transistor is connected to the control terminal of the first transistor and to the third terminal such that the third terminal is connected to the control terminal of the first transistor through the fifth transistor. Finally, the decoder element has a sixth transistor of the second conductivity type with a control terminal, a first connection connected to the potential terminal, and a second connection connected to the control terminal of the first transistor such that the control terminal of the first transistor can be connected to the potential terminal through the sixth transistor. The second terminal is connected to the control terminal of the fifth transistor and to the control terminal of the sixth transistor.
In accordance with an added feature of the invention, in order to generate the output signal having a value of the second potential, the first potential or the second potential is present at the first terminal, and the third potential is present at both the second terminal and the third terminal.
In accordance with an additional feature of the invention, in order to generate the output signal having a value of the third potential, the first potential or the second potential is present at the first terminal, the third potential is present at the second terminal and the first potential is present at the third terminal.
With the foregoing and other objects in view there is further provided, in accordance with the invention, a decoder circuit formed of first and second decoder elements as described above. The third terminal of the first decoder element is connected to the third terminal of the second decoder element.
With the foregoing and other objects in view there is further provided, in accordance with the invention, a method for operating decoder elements, which includes providing a decoder element as described above. The output signal having the first potential is generated by applying the first potential to the second terminal. A change-over from the third potential to the first potential is then impressed on the third terminal, and subsequently a change-over from the second potential to the first potential is impressed on the first terminal.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a decoder element for generating an output signal having three different potentials and an operating method for the decoder element, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.